DNA polymerase is relied upon by all organisms to replicate and maintain their genomes. They allow high fidelity replication of DNA by detecting complementarity between bases as well as recognizing additional structural features of the base. Three main super families of DNA polymerases exist based upon their amino acid similarity to E. Coli DNA polymerases I, II and III. They are called Family A, B and C polymerases, respectively. Family A and B polymerases have a common structural core for the nucleotide binding site.
Early experiments with DNA polymerases revealed difficulties incorporating modified nucleotides such as dideoxy-nucleotides (ddNTPs). Therefore, there are several examples in which DNA polymerases have been modified to increase the rates of incorporation of nucleotide analogues. There is a need to develop a recombinant DNA polymerase capable of incorporating 3′-esterified nucleotide analogues or 3′-ester-dye nucleotide analogues with quencher linked to phosphate group such as 3′-ester-dye/5′-Q, wherein Q represents quencher.